NCERT Class 9 Solutions: Statistics (Chapter 14) Exercise 14.1

Q-1 Give five examples of data that you can collect from day to day life.

Solution:

Number of females per 1000 males in various states of our country

Weights of students of our class

Production of wheat in the last 10 year in our country

Number of plants in our locality

Rainfall in our city in the last 10 years

Q-2 Classify the data in Q1 above as primary or secondary data.

Solution:

The information which is collected by the investigator himself with a definite objective in his mind is called primary data. Primary data can be explained and is usually collected by researcher themselves. They are collected from sources such as personal interviews, questionnaires or surveys with a specific intention and on a specific subject. Of course, it is cumbersome to collect primary data, but it provides first-hand and fine tailored information.

When the information is gathered from a source which already had the information stored, it is called secondary data. Secondary data is already available somewhere, whether it be in journals, on the internet, in records or in governmental archives. Since historical data cannot be collected, researcher has to rely on secondary sources for such data.

From the above, data in 1, 3, and 5 is secondary data. Such data would have been collected respective government agencies. For example 1 would be collected as part of census, 3 would be available with agriculture department and 5 would be available with weather department. Data in 2 and 4 is primary data and is unlikely to be already collected by some other authority or entity.